Impeller for catheter pump

Abstract

An impeller for a pump is disclosed herein. The impeller can include a hub having a fixed end and a free end. The impeller can also have a plurality of blades supported by the hub. Each blade can have a fixed end coupled to the hub and a free end. The impeller can have a stored configuration and a deployed configuration, the blades in the deployed configuration extending away from the hub, and the blades in the stored configuration being compressed against the hub.

What is claimed is: 
     
       1. An impeller for a pump, the impeller comprising:
 a hub having a proximal end portion and a distal end portion; 
 a blade supported by the hub, the blade having a fixed end coupled to the hub and a free end, the impeller having a stored configuration when the impeller is at rest, a deployed configuration when the impeller is at rest, and an operational configuration when the impeller rotates in a rotational direction, the blade in the deployed and operational configurations extending away from the hub, and the blade in the stored configuration being compressed against the hub, 
 wherein the blade in the operational configuration is deformed relative to the deployed configuration in a direction opposite to the rotational direction. 
 
     
     
       2. The impeller of  claim 1 , wherein the curved surface is sized and shaped to substantially conform to the shape of the hub when the impeller is in the stored configuration. 
     
     
       3. The impeller of  claim 1 , wherein a height of the blade in the operational configuration is greater than a height of the blade in the deployed configuration. 
     
     
       4. The impeller of  claim 1 , wherein, relative to the deployed configuration, the blade deforms radially outwardly when in the operational configuration. 
     
     
       5. The impeller of  claim 1 , wherein the blade has a leading edge and a trailing edge, wherein a ramped surface is formed at the trailing edge of the blade, the ramped surface configured to bear against a sheath to urge the impeller into the stored configuration. 
     
     
       6. The impeller of  claim 1 , wherein the hub has a first diameter at the proximal portion end of the hub and a second diameter at the distal end portion of the hub, the first diameter larger than the second diameter. 
     
     
       7. The impeller of  claim 1 , wherein the impeller has a diameter in the stored configuration corresponding to a catheter size between about 8 FR and about 21 FR, and a diameter in the deployed configuration corresponding to a catheter size above about 12 FR. 
     
     
       8. The impeller of  claim 7 , wherein the impeller has a diameter in the stored configuration corresponding to a catheter size between about 12 FR and about 21 FR, and a diameter in the deployed configuration corresponding to a catheter size above about 21 FR. 
     
     
       9. The impeller of  claim 1 , further comprising a plurality of blades. 
     
     
       10. The impeller of  claim 1 , wherein the blade includes a curved surface having a radius of curvature, the radius of curvature being about the same in the stored configuration and the deployed configuration. 
     
     
       11. The impeller of  claim 10 , wherein the radius of curvature in the deployed configuration is in a range of 0.06 inches to 0.155 inches. 
     
     
       12. The impeller of  claim 1 , wherein the impeller comprises three blades. 
     
     
       13. The impeller of  claim 1 , wherein, in the operational configuration, the blade is deformed at least in part towards the distal end portion of the hub. 
     
     
       14. An impeller for a pump, the impeller comprising:
 a hub having a proximal end portion and a distal end portion; 
 a blade supported by the hub, the blade having a fixed end coupled to the hub and a free end, the impeller having a stored configuration when the impeller is at rest, a deployed configuration when the impeller is at rest, and an operational configuration when the impeller rotates, the blade in the deployed and operational configurations extending away from the hub, and the blade in the stored configuration being compressed against the hub, 
 wherein the blade has a higher stiffness at the free end of the blade than at the fixed end of the blade. 
 
     
     
       15. The impeller of  claim 14 , wherein the blade has a first thickness at the fixed end of the blade and a second thickness at the free end of the blade, the second thickness greater than the first thickness. 
     
     
       16. An impeller for a pump, the impeller comprising:
 a hub having a proximal end portion and a distal end portion; 
 a blade supported by the hub, the blade having a fixed end coupled to the hub and a free end, the impeller having a stored configuration when the impeller is at rest, a deployed configuration when the impeller is at rest, and an operational configuration when the impeller rotates, the blade in the deployed and operational configurations extending away from the hub, and the blade in the stored configuration being compressed against the hub, 
 wherein the blade comprises a first blade angle defined near a distal end of the blade and extending between a plane perpendicular to the free end of the blade and a plane perpendicular to the hub, wherein the blade comprises a second blade angle defined near a proximal end of the blade and extending between a plane perpendicular to the free end of the blade and a plane perpendicular to the hub, and wherein the first blade angle is larger than the second blade angle. 
 
     
     
       17. An impeller for a pump, the impeller comprising:
 a hub having a proximal end portion and a distal end portion; 
 a blade supported by the hub, the blade having a fixed end coupled to the hub and a free end, the impeller having a stored configuration when the impeller is at rest, a deployed configuration when the impeller is at rest, and an operational configuration when the impeller rotates, the blade in the deployed and operational configurations extending away from the hub, and the blade in the stored configuration being compressed against the hub, 
 wherein the blade has a suction side and a pressure side, the impeller further comprising a first fillet formed at the fixed end of the blade on the suction side of the blade, wherein the first fillet is sized and shaped to support the blade when the impeller rotates in an operational configuration. 
 
     
     
       18. The impeller of  claim 17 , further comprising a second fillet formed at the fixed end of the blade on the pressure side of the blade, wherein the second fillet is sized and shaped to urge the impeller into the stored configuration when an axial force is applied to the blades. 
     
     
       19. A percutaneous heart pump, the pump comprising:
 a catheter body; 
 an impeller coupled to a distal end portion of the catheter body and having a stored configuration, a deployed configuration, and an operational configuration in which the impeller rotates about a rotational direction, the impeller comprising:
 a hub; 
 a blade supported by the hub and having a front end portion and a back end portion, the blade including a ramped surface at the back end portion, the blade in the operational configuration deformed relative to the deployed configuration in a direction opposite to the rotational direction; and 
 a sheath disposed about the catheter body and having a proximal end and a distal end, wherein the distal end of the sheath is configured to compress the blade from the deployed configuration to the stored configuration when the distal end of the sheath is urged against the ramped surface of the blade. 
 
 
     
     
       20. The percutaneous heart pump of  claim 19 , further comprising an expandable cannula coupled to the distal end portion of the catheter body, the impeller disposed within the expandable cannula, wherein the distal end of the sheath is configured to bear against the expandable cannula such that the expandable cannula contacts the ramped surface of the blade to compress the blade to the stored configuration. 
     
     
       21. A method for storing an impeller, the method comprising:
 urging a sheath against a ramped surface of a back end of a blade of an impeller, the impeller having one or more blades, the impeller having a stored configuration, a deployed configuration, and an operational configuration in which the impeller rotates about a rotational direction, each blade in the stored configuration compressed against a hub of the impeller and each blade in the deployed configuration extending away from the hub, the blade in the operational configuration deformed relative to the deployed configuration in a direction opposite to the rotational direction; and 
 collapsing the blade against the hub to urge the impeller into the stored configuration. 
 
     
     
       22. The method of  claim 21 , wherein the impeller is disposed within an expandable cannula, the method further comprising advancing the sheath over the impeller and the expandable cannula to store the impeller and expandable cannula within the sheath. 
     
     
       23. The method of  claim 22 , wherein urging the sheath against the ramped surface comprises contacting a distal end of the sheath against a contact portion of the expandable cannula. 
     
     
       24. The method of  claim 22 , wherein contacting the sheath against the ramped surface comprises axially displacing the sheath relative to the expandable cannula and the impeller.